Mongoose $lookup count references
up vote
0
down vote
favorite
Here's my simplified schema for my MongoDB database that I'm working on:
const podcastSchema: Schema = new Schema({
name: { type: String, required: true },
episodes: {
type: [{
title: { type: String, required: true },
}],
default: undefined
}
},{
timestamps: true
});
I've added a schema for stats, basically a listen count for each episode of the podcast:
const statisticSchema: Schema = new Schema({
connectionIdentifier: { type: String, required: true },
episode: { type: Schema.Types.ObjectId, ref: 'Podcast.Episodes' }
},{
timestamps: true
});
Now I need to join (left outer join actually) for each episode in podcast the count of items in stats, so I can have something like this:
podcasts: {
name: 'Lorem'
episodes: [{
title: 'Ipsum',
played: 323
},{
title: 'Dolor',
played: 12
},
...
]
}
This is what I came from:
const episodes = await Podcast.aggregate([
{ $match: { _id: podcastId } }, {
$lookup: {
from: 'statistics',
localField: 'episodes._id',
foreignField: 'episode',
as: 'resultingEpisodeArray'
}
},{
$unwind: { path: '$resultingEpisodeArray', preserveNullAndEmptyArrays: true }
},{
$group: {
_id: null,
episode: { $push: '$episodes' },
played: { $sum: 1 }
}
},{
$project: {
_id: '$episode._id',
title: '$episode.
played: '$played'
}
}
]);
But it aggregate all podcast in a single one.
Where I'm failing?
Thanks for the help!
node.js mongodb mongoose
edited Nov 19 at 19:59
kit
1,1081516
asked Nov 19 at 16:13
Valerio
416519
add a comment |
up vote
0
down vote
favorite
Here's my simplified schema for my MongoDB database that I'm working on:
const podcastSchema: Schema = new Schema({
name: { type: String, required: true },
episodes: {
type: [{
title: { type: String, required: true },
}],
default: undefined
}
},{
timestamps: true
});
I've added a schema for stats, basically a listen count for each episode of the podcast:
const statisticSchema: Schema = new Schema({
connectionIdentifier: { type: String, required: true },
episode: { type: Schema.Types.ObjectId, ref: 'Podcast.Episodes' }
},{
timestamps: true
});
Now I need to join (left outer join actually) for each episode in podcast the count of items in stats, so I can have something like this:
podcasts: {
name: 'Lorem'
episodes: [{
title: 'Ipsum',
played: 323
},{
title: 'Dolor',
played: 12
},
...
]
}
This is what I came from:
const episodes = await Podcast.aggregate([
{ $match: { _id: podcastId } }, {
$lookup: {
from: 'statistics',
localField: 'episodes._id',
foreignField: 'episode',
as: 'resultingEpisodeArray'
}
},{
$unwind: { path: '$resultingEpisodeArray', preserveNullAndEmptyArrays: true }
},{
$group: {
_id: null,
episode: { $push: '$episodes' },
played: { $sum: 1 }
}
},{
$project: {
_id: '$episode._id',
title: '$episode.
played: '$played'
}
}
]);
But it aggregate all podcast in a single one.
Where I'm failing?
Thanks for the help!
node.js mongodb mongoose
edited Nov 19 at 19:59
kit
1,1081516
asked Nov 19 at 16:13
Valerio
416519
1
Unclear what you are asking. Where isepisodes._idinPodcast? And you can simply use$sizeto count the number of elements inresultingEpisodeArray. Not sure why you used$grouphere?
– Anthony Winzlet
Nov 19 at 16:23
@AnthonyWinzlet, the _id is auto generated. I'll check your suggestions
– Valerio
Nov 20 at 9:07
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
Here's my simplified schema for my MongoDB database that I'm working on:
const podcastSchema: Schema = new Schema({
name: { type: String, required: true },
episodes: {
type: [{
title: { type: String, required: true },
}],
default: undefined
}
},{
timestamps: true
});
I've added a schema for stats, basically a listen count for each episode of the podcast:
const statisticSchema: Schema = new Schema({
connectionIdentifier: { type: String, required: true },
episode: { type: Schema.Types.ObjectId, ref: 'Podcast.Episodes' }
},{
timestamps: true
});
Now I need to join (left outer join actually) for each episode in podcast the count of items in stats, so I can have something like this:
podcasts: {
name: 'Lorem'
episodes: [{
title: 'Ipsum',
played: 323
},{
title: 'Dolor',
played: 12
},
...
]
}
This is what I came from:
const episodes = await Podcast.aggregate([
{ $match: { _id: podcastId } }, {
$lookup: {
from: 'statistics',
localField: 'episodes._id',
foreignField: 'episode',
as: 'resultingEpisodeArray'
}
},{
$unwind: { path: '$resultingEpisodeArray', preserveNullAndEmptyArrays: true }
},{
$group: {
_id: null,
episode: { $push: '$episodes' },
played: { $sum: 1 }
}
},{
$project: {
_id: '$episode._id',
title: '$episode.
played: '$played'
}
}
]);
But it aggregate all podcast in a single one.
Where I'm failing?
Thanks for the help!
node.js mongodb mongoose
edited Nov 19 at 19:59
kit
1,1081516
asked Nov 19 at 16:13
Valerio
416519
Here's my simplified schema for my MongoDB database that I'm working on:
const podcastSchema: Schema = new Schema({
name: { type: String, required: true },
episodes: {
type: [{
title: { type: String, required: true },
}],
default: undefined
}
},{
timestamps: true
});
I've added a schema for stats, basically a listen count for each episode of the podcast:
const statisticSchema: Schema = new Schema({
connectionIdentifier: { type: String, required: true },
episode: { type: Schema.Types.ObjectId, ref: 'Podcast.Episodes' }
},{
timestamps: true
});
Now I need to join (left outer join actually) for each episode in podcast the count of items in stats, so I can have something like this:
podcasts: {
name: 'Lorem'
episodes: [{
title: 'Ipsum',
played: 323
},{
title: 'Dolor',
played: 12
},
...
]
}
This is what I came from:
const episodes = await Podcast.aggregate([
{ $match: { _id: podcastId } }, {
$lookup: {
from: 'statistics',
localField: 'episodes._id',
foreignField: 'episode',
as: 'resultingEpisodeArray'
}
},{
$unwind: { path: '$resultingEpisodeArray', preserveNullAndEmptyArrays: true }
},{
$group: {
_id: null,
episode: { $push: '$episodes' },
played: { $sum: 1 }
}
},{
$project: {
_id: '$episode._id',
title: '$episode.
played: '$played'
}
}
]);
But it aggregate all podcast in a single one.
Where I'm failing?
Thanks for the help!
node.js mongodb mongoose
node.js mongodb mongoose
edited Nov 19 at 19:59
kit
1,1081516
asked Nov 19 at 16:13
Valerio
416519
edited Nov 19 at 19:59
kit
1,1081516
asked Nov 19 at 16:13
Valerio
416519
edited Nov 19 at 19:59
kit
1,1081516
edited Nov 19 at 19:59
kit
1,1081516
edited Nov 19 at 19:59
kit
1,1081516
1,1081516
asked Nov 19 at 16:13
Valerio
416519
asked Nov 19 at 16:13
Valerio
416519
asked Nov 19 at 16:13
Valerio
416519
416519
1
Unclear what you are asking. Where isepisodes._idinPodcast? And you can simply use$sizeto count the number of elements inresultingEpisodeArray. Not sure why you used$grouphere?
– Anthony Winzlet
Nov 19 at 16:23
@AnthonyWinzlet, the _id is auto generated. I'll check your suggestions
– Valerio
Nov 20 at 9:07
add a comment |
1
Unclear what you are asking. Where isepisodes._idinPodcast? And you can simply use$sizeto count the number of elements inresultingEpisodeArray. Not sure why you used$grouphere?
– Anthony Winzlet
Nov 19 at 16:23
@AnthonyWinzlet, the _id is auto generated. I'll check your suggestions
– Valerio
Nov 20 at 9:07
1
1
Unclear what you are asking. Where is
episodes._id in Podcast? And you can simply use $size to count the number of elements in resultingEpisodeArray. Not sure why you used $group here?– Anthony Winzlet
Nov 19 at 16:23
Unclear what you are asking. Where is
episodes._id in Podcast? And you can simply use $size to count the number of elements in resultingEpisodeArray. Not sure why you used $group here?– Anthony Winzlet
Nov 19 at 16:23
@AnthonyWinzlet, the _id is auto generated. I'll check your suggestions
– Valerio
Nov 20 at 9:07
@AnthonyWinzlet, the _id is auto generated. I'll check your suggestions
– Valerio
Nov 20 at 9:07
add a comment |
1 Answer
1
active
oldest
votes
up vote
0
down vote
accepted
Thanks to @AnthonyWinzlet suggestion, I got my errors. I really, really need to forget SQL when working on mongo.
For the sake of knowledge, here's the modified code that solved my issue:
const episodes = await Podcast.aggregate([
{ $match: { _id: podcastId } },
{ $unwind: '$episodes' },
{
$lookup: {
from: 'statistics',
localField: 'episodes._id',
foreignField: 'episode',
as: 'resultingEpisodeArray'
}
},
{
$project: {
_id: '$episodes._id',
title: '$episodes.title',
played: { $size: '$resultingEpisodeArray' }
}
},
]);
Again, kudos to Anthony for pointing me to the right direction!
answered Nov 20 at 9:25
Valerio
416519
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
accepted
Thanks to @AnthonyWinzlet suggestion, I got my errors. I really, really need to forget SQL when working on mongo.
For the sake of knowledge, here's the modified code that solved my issue:
const episodes = await Podcast.aggregate([
{ $match: { _id: podcastId } },
{ $unwind: '$episodes' },
{
$lookup: {
from: 'statistics',
localField: 'episodes._id',
foreignField: 'episode',
as: 'resultingEpisodeArray'
}
},
{
$project: {
_id: '$episodes._id',
title: '$episodes.title',
played: { $size: '$resultingEpisodeArray' }
}
},
]);
Again, kudos to Anthony for pointing me to the right direction!
answered Nov 20 at 9:25
Valerio
416519
add a comment |
up vote
0
down vote
accepted
Thanks to @AnthonyWinzlet suggestion, I got my errors. I really, really need to forget SQL when working on mongo.
For the sake of knowledge, here's the modified code that solved my issue:
const episodes = await Podcast.aggregate([
{ $match: { _id: podcastId } },
{ $unwind: '$episodes' },
{
$lookup: {
from: 'statistics',
localField: 'episodes._id',
foreignField: 'episode',
as: 'resultingEpisodeArray'
}
},
{
$project: {
_id: '$episodes._id',
title: '$episodes.title',
played: { $size: '$resultingEpisodeArray' }
}
},
]);
Again, kudos to Anthony for pointing me to the right direction!
answered Nov 20 at 9:25
Valerio
416519
add a comment |
up vote
0
down vote
accepted
up vote
0
down vote
accepted
Thanks to @AnthonyWinzlet suggestion, I got my errors. I really, really need to forget SQL when working on mongo.
For the sake of knowledge, here's the modified code that solved my issue:
const episodes = await Podcast.aggregate([
{ $match: { _id: podcastId } },
{ $unwind: '$episodes' },
{
$lookup: {
from: 'statistics',
localField: 'episodes._id',
foreignField: 'episode',
as: 'resultingEpisodeArray'
}
},
{
$project: {
_id: '$episodes._id',
title: '$episodes.title',
played: { $size: '$resultingEpisodeArray' }
}
},
]);
Again, kudos to Anthony for pointing me to the right direction!
answered Nov 20 at 9:25
Valerio
416519
Thanks to @AnthonyWinzlet suggestion, I got my errors. I really, really need to forget SQL when working on mongo.
For the sake of knowledge, here's the modified code that solved my issue:
const episodes = await Podcast.aggregate([
{ $match: { _id: podcastId } },
{ $unwind: '$episodes' },
{
$lookup: {
from: 'statistics',
localField: 'episodes._id',
foreignField: 'episode',
as: 'resultingEpisodeArray'
}
},
{
$project: {
_id: '$episodes._id',
title: '$episodes.title',
played: { $size: '$resultingEpisodeArray' }
}
},
]);
Again, kudos to Anthony for pointing me to the right direction!
answered Nov 20 at 9:25
Valerio
416519
answered Nov 20 at 9:25
Valerio
416519
answered Nov 20 at 9:25
Valerio
416519
answered Nov 20 at 9:25
Valerio
416519
416519
add a comment |
add a comment |
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1
Unclear what you are asking. Where is
episodes._idinPodcast? And you can simply use$sizeto count the number of elements inresultingEpisodeArray. Not sure why you used$grouphere?– Anthony Winzlet
Nov 19 at 16:23
@AnthonyWinzlet, the _id is auto generated. I'll check your suggestions
– Valerio
Nov 20 at 9:07